Geologic formations are used for many purposes such as hydrocarbon production, geothermal production and carbon dioxide sequestration. Boreholes are typically drilled into an earth formation in order to intersect and/or access the formation. Various types of drillstrings may be deployed in a borehole. A drillstring, also known as a drilling assembly, generally includes components, such as those making up a drill pipe or a bottomhole assembly. The bottomhole assembly contains drill collars which may be instrumented and can be used to obtain measurements-while-drilling or -while-logging.
Some drillstrings can include components that allow the borehole to be drilled in directions other than vertical. Such drilling is referred to in the industry as “directional drilling.” While deployed in the borehole, the components of the drillstring may be subject to a variety of forces or strains.
Trajectory changes, either planned (i.e., directional drilling) or unplanned (e.g., azimuthal walk), may result in the creation of a non-linearity (or deviation) in the borehole, such as a dogleg. A dogleg is a section in a borehole where the trajectory of the borehole changes, e.g., drillbit inclination or azimuth changes. This trajectory change may introduce or alter a rate of curvature over a length of the borehole. One measure of the rate of curvature (or rate of trajectory change) may be referred to as dogleg severity (‘DLS’). DLS may be measured between consecutive survey stations along the wellbore trajectory.